Hi,

I have started using the AMI filters instead of static AMI configuration: https://github.com/jenkinsci/ec2-plugin/pull/533/commits/759e1fd10fe8ad9881d699fca198b081c8faed74 and noticed that 'Check Current Spot Price' funtionality shows price for on-demand instances if 'AMI ID' is not specified.

STR:

• Configure ec2 plugin and template to use spot configuration;
• Press 'Check Current Spot Price' button and you will see the correct price
• remove the field 'AMI ID'
• Press 'Check Current Spot Price' button one more time

Actual Result:

ec2-plugin shows the price for on-demand instances now...

I attached the screen-shots.